Solid state image sensors, such as charge-coupled devices (CCD) and CMOS (complementary metal oxide semiconductor) image sensors (CIS) are commonly used as input devices for electronic video and still cameras, robotic/machine vision and other imaging devices. These image sensors include a light sensing element, i.e. a photodiode, within an individual pixel. The pixels are arranged into two-dimensional rows and columns as pixel arrays. The light data captured by the plurality of the light sensing pixels arranged in the pixel array is processed using associated logic and analog circuits. The various circuits include column circuits associated with a column of pixels of the pixel array and row circuits associated with rows of pixels of the pixel arrays. The circuits perform various functions and each column of the pixel array has an associated column circuit and each row of the pixel array has an associated row circuit. In two-dimensional CMOS image sensors, the column circuits and row circuits surround the pixel array.
In today's rapidly advancing electronics industry, and especially in the electronics imaging industry, there is a continued push for increased miniaturization of the various components, including the chips upon which image sensors are formed. There is also a drive to produce image sensors with maximized imaging capabilities. An image sensor with minimal foot print is essential for the compact camera modules used in mobile devices like smart phones and tablet computers.